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Yeh WC, Hsu CY, Li KY, Chien CF, Huang LC, Yang YH. Association between subclinical epileptiform discharge and the behavioral and psychological symptoms in patients with Alzheimer's dementia. Int J Geriatr Psychiatry 2023; 38:e6013. [PMID: 37817385 DOI: 10.1002/gps.6013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 09/25/2023] [Indexed: 10/12/2023]
Abstract
OBJECTIVES Behavioral and psychological symptoms of dementia (BPSD) are highly prevalent in patients with Alzheimer's disease (AD), causing burdens on caregivers. Behavioral and psychological symptoms of dementia and subclinical epileptiform discharge (SED) increased with the disease course of AD. However, the interaction between them was still unknown. The present study aimed to evaluate the associations between SED and BPSD. METHODS/DESIGN Patients with AD from Kaohsiung Municipal Ta-tung Hospital were included in this study. International 10-20 system scalp electroencephalography (EEG) for 13 min was performed to detect SED. Behavioral and psychological symptoms of dementia was assessed by neuropsychiatric inventory (NPI) questionnaires. The occurrence of BPSD subsyndromes was compared between patients with and without SED. RESULTS Two hundred sixty-three adult patients qualified for the inclusion criteria and were enrolled in this study. The mean age of patients was 80.2 years, and approximately 62% were women. 17.1% of patients showed SED on EEG. Apathy was the most commonly reported BPSD subsyndrome in this cohort. There was no significant difference in the prevalence of BPSD between patients with and without SED. (75.6% vs. 67.4%, p = 0.2806). However, the NPI score of irritability subsyndrome was significantly higher in the SED (+) group (2.6 ± 3.7 vs. 1.2 ± 2.7, p = 0.0028). In addition, subclinical epileptiform discharge in the frontal lobe was associated with a considerably higher occurrence of hyperactivity subsyndrome, including irritability. CONCLUSIONS SED may not be a direct cause of BPSD, but the presence of SED may affect the manifestation of BPSD.
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Affiliation(s)
- Wei-Chih Yeh
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Neurology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chung-Yao Hsu
- Department of Neurology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Kuan-Ying Li
- Department of Neurology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ching-Fang Chien
- Department of Neurology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ling-Chun Huang
- Department of Neurology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yuan-Han Yang
- Department of Neurology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
- Post-baccalaureate Medicine, Kaohsiung Medical, University, Kaohsiung, Taiwan
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2
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Lee DA, Lee HJ, Park KM. Structural brain network analysis in occipital lobe epilepsy. BMC Neurol 2023; 23:268. [PMID: 37454057 PMCID: PMC10349483 DOI: 10.1186/s12883-023-03326-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 07/09/2023] [Indexed: 07/18/2023] Open
Abstract
BACKGROUND This study aimed to analyze the structural brain network in patients with occipital lobe epilepsy (OLE) and investigate the differences in structural brain networks between patients with OLE and healthy controls. METHODS Patients with OLE and healthy controls with normal brain MRI findings were enrolled. They underwent diffusion tensor imaging using a 3.0T MRI scanner, and we computed the network measures of global and local structural networks in patients with OLE and healthy controls using the DSI studio program. We compared network measures between the groups. RESULTS We enrolled 23 patients with OLE and 42 healthy controls. There were significant differences in the global structural network between patients with OLE and healthy controls. The assortativity coefficient (-0.0864 vs. -0.0814, p = 0.0214), mean clustering coefficient (0.0061 vs. 0.0064, p = 0.0203), global efficiency (0.0315 vs. 0.0353, p = 0.0086), and small-worldness index (0.0001 vs. 0.0001, p = 0.0175) were lower, whereas the characteristic path length (59.2724 vs. 53.4684, p = 0.0120) was higher in patients with OLE than those in the healthy controls. There were several nodes beyond the occipital lobe that showed significant differences in the local structural network between the groups. In addition, the assortativity coefficient was negatively correlated with the duration of epilepsy (r=-0.676, p = 0.001).
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Affiliation(s)
- Dong Ah Lee
- Department of Neurology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - Ho-Joon Lee
- Department of Radiology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - Kang Min Park
- Department of Neurology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
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3
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Liu Y, Li Q, Yi D, Duan J, Zhang Q, Huang Y, He H, Liao Y, Song Z, Deng L, Wang W, Liu D. Topological abnormality of structural covariance network in MRI-negative frontal lobe epilepsy. Front Neurosci 2023; 17:1136110. [PMID: 37214387 PMCID: PMC10196002 DOI: 10.3389/fnins.2023.1136110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 04/11/2023] [Indexed: 05/24/2023] Open
Abstract
Background Frontal lobe epilepsy (FLE) is the second most common type of focal epilepsy, however, imaging studies of FLE have been far less than Temporal lobe epilepsy (TLE) and the structural findings were not consistent in previous literature. Object Investigate the changes in cortical thickness in patients with FLE and the alteration of the structural covariance networks (SCNs) of cortical thickness with graph-theory. Method Thirty patients with FLE (18 males/12 females; 28.33 ± 11.81 years) and 27 demographically matched controls (15 males/12 females; 29.22 ± 9.73 years) were included in this study with high-resolution structural brain MRI scans. The cortical thickness was calculated, and structural covariance network (SCN) of cortical thickness were reconstructed using 68 × 68 matrix and analyzed with graph-theory approach. Result Cortical thickness was not significantly different between two groups, but path length and node betweenness were significantly increased in patients with FLE, and the regional network alterations were significantly changed in right precentral gyrus and right temporal pole (FDR corrected, p < 0.05). Comparing to HC group, network hubs were decreased and shifted away from frontal lobe. Conclusion The topological properties of cortical thickness covariance network were significantly altered in patients with FLE, even without obvious surface-based morphological damage. Graph-theory based SCN analysis may provide sensitive neuroanatomical biomarkers for FLE.
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Affiliation(s)
- Yin Liu
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Quanji Li
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Dali Yi
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Junhong Duan
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Qingxia Zhang
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yunchen Huang
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Haibo He
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yunjie Liao
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Zhi Song
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Lingling Deng
- Department of Radiology, The Second Affiliated Hospital, University of South China, Hengyang, China
| | - Wei Wang
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Ding Liu
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
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4
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Benzait A, Krenz V, Wegrzyn M, Doll A, Woermann F, Labudda K, Bien CG, Kissler J. Hemodynamic correlates of emotion regulation in frontal lobe epilepsy patients and healthy participants. Hum Brain Mapp 2023; 44:1456-1475. [PMID: 36366744 PMCID: PMC9921231 DOI: 10.1002/hbm.26133] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 09/15/2022] [Accepted: 10/11/2022] [Indexed: 11/13/2022] Open
Abstract
The ability to regulate emotions is indispensable for maintaining psychological health. It heavily relies on frontal lobe functions which are disrupted in frontal lobe epilepsy. Accordingly, emotional dysregulation and use of maladaptive emotion regulation strategies have been reported in frontal lobe epilepsy patients. Therefore, it is of clinical and scientific interest to investigate emotion regulation in frontal lobe epilepsy. We studied neural correlates of upregulating and downregulating emotions toward aversive pictures through reappraisal in 18 frontal lobe epilepsy patients and 17 healthy controls using functional magnetic resonance imaging. Patients tended to report more difficulties with impulse control than controls. On the neural level, patients had diminished activity during upregulation in distributed left-sided regions, including ventrolateral and dorsomedial prefrontal cortex, angular gyrus and anterior temporal gyrus. Patients also showed less activity than controls in the left precuneus for upregulation compared to downregulation. Unlike controls, they displayed no task-related activity changes in the left amygdala, whereas the right amygdala showed task-related modulations in both groups. Upregulation-related activity changes in the left inferior frontal gyrus, insula, orbitofrontal cortex, anterior and posterior cingulate cortex, and precuneus were correlated with questionnaire data on habitual emotion regulation. Our results show that structural or functional impairments in the frontal lobes disrupt neural mechanisms underlying emotion regulation through reappraisal throughout the brain, including posterior regions involved in semantic control. Findings on the amygdala as a major target of emotion regulation are in line with the view that specifically the left amygdala is connected with semantic processing networks.
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Affiliation(s)
- Anissa Benzait
- Department of Psychology, Bielefeld University, Bielefeld, Germany
| | - Valentina Krenz
- Department of Psychology, University of Hamburg, Hamburg, Germany
| | - Martin Wegrzyn
- Department of Psychology, Bielefeld University, Bielefeld, Germany
| | - Anna Doll
- Department of Psychology, Bielefeld University, Bielefeld, Germany.,Department of Epileptology (Mara Hospital), Medical School, Bielefeld University, Bielefeld, Germany
| | - Friedrich Woermann
- Department of Epileptology (Mara Hospital), Medical School, Bielefeld University, Bielefeld, Germany
| | - Kirsten Labudda
- Department of Psychology, Bielefeld University, Bielefeld, Germany
| | - Christian G Bien
- Department of Epileptology (Mara Hospital), Medical School, Bielefeld University, Bielefeld, Germany
| | - Johanna Kissler
- Department of Psychology, Bielefeld University, Bielefeld, Germany.,Center of Excellence Cognitive Interaction Technology (CITEC), Bielefeld University, Bielefeld, Germany
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5
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Jang SJ, Yang YJ, Ryun S, Kim JS, Chung CK, Jeong J. Decoding trajectories of imagined hand movement using electrocorticograms for brain-machine interface. J Neural Eng 2022; 19. [PMID: 35985293 DOI: 10.1088/1741-2552/ac8b37] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 08/19/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Reaching hand movement is an important motor skill actively examined in brain-computer interface (BCI). Among various components of movement analyzed is the hand's trajectory, which describes the hand's continuous positions in three-dimensional space. While a large body of studies have investigated the decoding of real movements and the reconstruction of real hand movement trajectories from neural signals, fewer studies have attempted to decode the trajectory of imagined hand movement. To develop BCI systems for patients with hand motor dysfunctions, the systems essentially require to achieve movement-free control of external devices, which is only possible through successful decoding of purely imagined hand movement. APPROACH To achieve this goal, this study used a machine learning technique (i.e., the variational Bayesian least square) to analyze the electrocorticogram (ECoG) of eighteen epilepsy patients obtained from when they performed movement execution (ME) and kinesthetic movement imagination (KMI) of the reach-and-grasp hand action. MAIN RESULTS The variational Bayesian decoding model was able to successfully predict the imagined trajectories of hand movement significantly above chance level. The Pearson's correlation coefficient between imagined and predicted trajectories was 0.3393 and 0.4936 for the KMI (KMI trials only) and MEKMI paradigm (alternating trials of ME and KMI) respectively. SIGNIFICANCE This study demonstrated a high accuracy of prediction for trajectories of imagined hand movement, and more importantly, higher decoding accuracy of imagined trajectories in the MEKMI paradigm than in the KMI paradigm solely.
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Affiliation(s)
- Sang Jin Jang
- Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, 411 E16-1(YBS Building) Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon, South Korea 34141, Daejeon, Daejeon, 34141, Korea (the Republic of)
| | - Yu Jin Yang
- Seoul National University College of Natural Sciences, 103, Daehak-ro, Jongno-gu, Seoul, Republic of Korea, Seoul, 03080, Korea (the Republic of)
| | - Seokyun Ryun
- Seoul National University College of Natural Sciences, 103, Daehak-ro, Jongno-gu, Seoul, Republic of Korea, Seoul, 03080, Korea (the Republic of)
| | - June Sic Kim
- Seoul National University College of Natural Sciences, 103, Daehak-ro, Jongno-gu, Seoul, Republic of Korea, Seoul, 03080, Korea (the Republic of)
| | - Chun Kee Chung
- Seoul National University College of Natural Sciences, 103, Daehak-ro, Jongno-gu, Seoul, Republic of Korea, Seoul, 03080, Korea (the Republic of)
| | - Jaeseung Jeong
- Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, 514 E16-1(YBS Building) Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon, South Korea 34141, Daejeon, 34141, Korea (the Republic of)
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6
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Soto-León V, Torres-Llacsa M, Mordillo-Mateos L, Carrasco-López C, Pineda-Pardo JA, Velasco AI, Abad-Toribio L, Tornero J, Foffani G, Strange BA, Oliviero A. Static magnetic field stimulation over motor cortex modulates resting functional connectivity in humans. Sci Rep 2022; 12:7834. [PMID: 35551490 PMCID: PMC9098424 DOI: 10.1038/s41598-022-11859-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 04/22/2022] [Indexed: 11/09/2022] Open
Abstract
Focal application of transcranial static magnetic field stimulation (tSMS) over the human motor cortex induces local changes in cortical excitability. Whether tSMS can also induce distant network effects, and how these local and distant effects may vary over time, is currently unknown. In this study, we applied 10 min tSMS over the left motor cortex of healthy subjects using a real/sham parallel design. To measure tSMS effects at the sensori-motor network level, we used resting-state fMRI. Real tSMS, but not sham, reduced functional connectivity within the stimulated sensori-motor network. This effect of tSMS showed time-dependency, returning to sham levels after the first 5 min of fMRI scanning. With 10 min real tSMS over the motor cortex we did not observe effects in other functional networks examined (default mode and visual system networks). In conclusion, 10 min of tSMS over a location within the sensori-motor network reduces functional connectivity within the same functional network.
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Affiliation(s)
- Vanesa Soto-León
- FENNSI Group, Hospital Nacional de Parapléjicos, SESCAM, Finca La Peraleda s/n, 45071, Toledo, Spain.
| | - Mabel Torres-Llacsa
- FENNSI Group, Hospital Nacional de Parapléjicos, SESCAM, Finca La Peraleda s/n, 45071, Toledo, Spain
| | - Laura Mordillo-Mateos
- FENNSI Group, Hospital Nacional de Parapléjicos, SESCAM, Finca La Peraleda s/n, 45071, Toledo, Spain.,Universidad de Castilla la Mancha, Talavera de la Reina, Toledo, Spain
| | - Carmen Carrasco-López
- FENNSI Group, Hospital Nacional de Parapléjicos, SESCAM, Finca La Peraleda s/n, 45071, Toledo, Spain.,IoTaP (Internet of Things and People), Malmö University, Malmö, Sweden
| | - José A Pineda-Pardo
- HM CINAC (Centro Integral de Neurociencias Abarca Campal), Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain
| | - Ana I Velasco
- Universidad Alfonso X El Sabio, Villanueva de la Cañada, Madrid, Spain
| | | | | | - Guglielmo Foffani
- HM CINAC (Centro Integral de Neurociencias Abarca Campal), Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain.,Neural Bioengineering Group, Hospital Nacional de Parapléjicos, SESCAM, Toledo, Spain
| | - Bryan A Strange
- Laboratory for Clinical Neuroscience, Centre of Biomedical Technology, Universidad Politécnica de Madrid, Madrid, Spain
| | - Antonio Oliviero
- FENNSI Group, Hospital Nacional de Parapléjicos, SESCAM, Finca La Peraleda s/n, 45071, Toledo, Spain. .,Hospital Los Madroños, Brunete, Madrid, Spain.
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7
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Zhu Q, Yang J, Xu B, Hou Z, Sun L, Zhang D. Multimodal Brain Network Jointly Construction and Fusion for Diagnosis of Epilepsy. Front Neurosci 2021; 15:734711. [PMID: 34658773 PMCID: PMC8511490 DOI: 10.3389/fnins.2021.734711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 08/10/2021] [Indexed: 11/24/2022] Open
Abstract
Brain network analysis has been proved to be one of the most effective methods in brain disease diagnosis. In order to construct discriminative brain networks and improve the performance of disease diagnosis, many machine learning–based methods have been proposed. Recent studies show that combining functional and structural brain networks is more effective than using only single modality data. However, in the most of existing multi-modal brain network analysis methods, it is a common strategy that constructs functional and structural network separately, which is difficult to embed complementary information of different modalities of brain network. To address this issue, we propose a unified brain network construction algorithm, which jointly learns both functional and structural data and effectively face the connectivity and node features for improving classification. First, we conduct space alignment and brain network construction under a unified framework, and then build the correlation model among all brain regions with functional data by low-rank representation so that the global brain region correlation can be captured. Simultaneously, the local manifold with structural data is embedded into this model to preserve the local structural information. Second, the PageRank algorithm is adaptively used to evaluate the significance of different brain regions, in which the interaction of multiple brain regions is considered. Finally, a multi-kernel strategy is utilized to solve the data heterogeneity problem and merge the connectivity as well as node information for classification. We apply the proposed method to the diagnosis of epilepsy, and the experimental results show that our method can achieve a promising performance.
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Affiliation(s)
- Qi Zhu
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Jing Yang
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Bingliang Xu
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Zhenghua Hou
- Department of Psychosomatics and Psychiatry, Affiliated Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Liang Sun
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Daoqiang Zhang
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, China
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8
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Structural and functional motor-network disruptions predict selective action-concept deficits: Evidence from frontal lobe epilepsy. Cortex 2021; 144:43-55. [PMID: 34637999 DOI: 10.1016/j.cortex.2021.08.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 07/12/2021] [Accepted: 08/05/2021] [Indexed: 12/22/2022]
Abstract
Built on neurodegenerative lesions models, the disrupted motor grounding hypothesis (DMGH) posits that motor-system alterations selectively impair action comprehension. However, major doubts remain concerning the dissociability, neural signatures, and etiological generalizability of such deficits. Few studies have compared action-concept outcomes between disorders affecting and sparing motor circuitry, and none has examined their multimodal network predictors via data-driven approaches. Here, we first assessed action- and object-concept processing in patients with frontal lobe epilepsy (FLE), patients with posterior cortex epilepsy (PCE), and healthy controls. Then, we examined structural and functional network signatures via diffusion tensor imaging and resting-state connectivity measures. Finally, we used these measures to predict behavioral performance with an XGBoost machine learning regression algorithm. Relative to controls, FLE (but not PCE) patients exhibited selective action-concept deficits together with structural and functional abnormalities along motor networks. The XGBoost model reached a significantly large effect size only for action-concept outcomes in FLE, mainly predicted by structural (cortico-spinal tract, anterior thalamic radiation, uncinate fasciculus) and functional (M1-parietal/supramarginal connectivity) motor networks. These results extend the DMGH, suggesting that action-concept deficits are dissociable markers of frontal/motor (relative to posterior) disruptions, directly related to the structural and functional integrity of motor networks, and traceable beyond canonical movement disorders.
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9
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Moguilner S, Birba A, Fino D, Isoardi R, Huetagoyena C, Otoya R, Tirapu V, Cremaschi F, Sedeño L, Ibáñez A, García AM. Multimodal neurocognitive markers of frontal lobe epilepsy: Insights from ecological text processing. Neuroimage 2021; 235:117998. [PMID: 33789131 PMCID: PMC8272524 DOI: 10.1016/j.neuroimage.2021.117998] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/15/2021] [Accepted: 03/24/2021] [Indexed: 01/07/2023] Open
Abstract
The pressing call to detect sensitive cognitive markers of frontal lobe epilepsy (FLE) remains poorly addressed. Standard frameworks prove nosologically unspecific (as they reveal deficits that also emerge across other epilepsy subtypes), possess low ecological validity, and are rarely supported by multimodal neuroimaging assessments. To bridge these gaps, we examined naturalistic action and non-action text comprehension, combined with structural and functional connectivity measures, in 19 FLE patients, 19 healthy controls, and 20 posterior cortex epilepsy (PCE) patients. Our analyses integrated inferential statistics and data-driven machine-learning classifiers. FLE patients were selectively and specifically impaired in action comprehension, irrespective of their neuropsychological profile. These deficits selectively and specifically correlated with (a) reduced integrity of the anterior thalamic radiation, a subcortical structure underlying motoric and action-language processing as well as epileptic seizure spread in this subtype; and (b) hypoconnectivity between the primary motor cortex and the left-parietal/supramarginal regions, two putative substrates of action-language comprehension. Moreover, machine-learning classifiers based on the above neurocognitive measures yielded 75% accuracy rates in discriminating individual FLE patients from both controls and PCE patients. Briefly, action-text assessments, combined with structural and functional connectivity measures, seem to capture ecological cognitive deficits that are specific to FLE, opening new avenues for discriminatory characterizations among epilepsy types.
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Affiliation(s)
- Sebastian Moguilner
- Global Brain Health Institute, UCSF, California, US, & Trinity College Dublin, Dublin, Ireland; Nuclear Medicine School Foundation (FUESMEN), National Commission of Atomic Energy (CNEA), Mendoza, Argentina
| | - Agustina Birba
- University of San Andres, Buenos Aires, Argentina; National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina
| | - Daniel Fino
- Nuclear Medicine School Foundation (FUESMEN), National Commission of Atomic Energy (CNEA), Mendoza, Argentina; Fundación Argentina para el Desarrollo en Salud, Mendoza, Argentina
| | - Roberto Isoardi
- Nuclear Medicine School Foundation (FUESMEN), National Commission of Atomic Energy (CNEA), Mendoza, Argentina
| | - Celeste Huetagoyena
- Neuromed, Clinical Neuroscience, Mendoza, Argentina; Universidad Católica Argentina
| | - Raúl Otoya
- Neuromed, Clinical Neuroscience, Mendoza, Argentina
| | - Viviana Tirapu
- Nuclear Medicine School Foundation (FUESMEN), National Commission of Atomic Energy (CNEA), Mendoza, Argentina; Neuromed, Clinical Neuroscience, Mendoza, Argentina
| | - Fabián Cremaschi
- Nuclear Medicine School Foundation (FUESMEN), National Commission of Atomic Energy (CNEA), Mendoza, Argentina; Neuroscience Department of the School of Medicine, National University of Cuyo, Mendoza, Argentina; Santa Isabel de Hungría Hospital, Mendoza, Argentina
| | - Lucas Sedeño
- National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina
| | - Agustín Ibáñez
- Global Brain Health Institute, UCSF, California, US, & Trinity College Dublin, Dublin, Ireland; University of San Andres, Buenos Aires, Argentina; National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina; Center for Social and Cognitive Neuroscience (CSCN), School of Psychology, Universidad Adolfo Ibáñez, Santiago, Chile
| | - Adolfo M García
- Global Brain Health Institute, UCSF, California, US, & Trinity College Dublin, Dublin, Ireland; University of San Andres, Buenos Aires, Argentina; National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina; Faculty of Education, National University of Cuyo (UNCuyo), Mendoza, Argentina; Departamento de Lingüística y Literatura, Facultad de Humanidades, Universidad de Santiago de Chile, Santiago, Chile.
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Takano T, Hayashi A, Harada Y. Progression of motor disability in cerebral palsy: The role of concomitant epilepsy. Seizure 2020; 80:81-85. [DOI: 10.1016/j.seizure.2020.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/12/2020] [Accepted: 06/07/2020] [Indexed: 10/24/2022] Open
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11
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Imaging Developmental and Interventional Plasticity Following Perinatal Stroke. Can J Neurol Sci 2020; 48:157-171. [DOI: 10.1017/cjn.2020.166] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
ABSTRACT:Perinatal stroke occurs around the time of birth and leads to lifelong neurological disabilities including hemiparetic cerebral palsy. Magnetic resonance imaging (MRI) has revolutionized our understanding of developmental neuroplasticity following early injury, quantifying volumetric, structural, functional, and metabolic compensatory changes after perinatal stroke. Such techniques can also be used to investigate how the brain responds to treatment (interventional neuroplasticity). Here, we review the current state of knowledge of how established and emerging neuroimaging modalities are informing neuroplasticity models in children with perinatal stroke. Specifically, we review structural imaging characterizing lesion characteristics and volumetrics, diffusion tensor imaging investigating white matter tracts and networks, task-based functional MRI for localizing function, resting state functional imaging for characterizing functional connectomes, and spectroscopy examining neurometabolic changes. Key challenges and exciting avenues for future investigations are also considered.
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12
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Fang S, Zhou C, Fan X, Jiang T, Wang Y. Epilepsy-Related Brain Network Alterations in Patients With Temporal Lobe Glioma in the Left Hemisphere. Front Neurol 2020; 11:684. [PMID: 32765403 PMCID: PMC7380082 DOI: 10.3389/fneur.2020.00684] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 06/08/2020] [Indexed: 12/12/2022] Open
Abstract
Background: Seizures are a common symptom in patients with temporal lobe gliomas and may result in brain network alterations. However, brain network changes caused by glioma-related epilepsy (GRE) remain poorly understood. Objective: In this study, we applied graph theory analysis to delineate topological networks with resting-state functional magnetic resonance images (rs-fMRI) and investigated characteristics of functional networks in patients with GRE. Methods: Thirty patients with low-grade gliomas in the left temporal lobe were enrolled and classified into GRE (n = 15) and non-GRE groups. Twenty healthy participants matched for age, sex, and education level were enrolled. All participants had rs-fMRI data. Sensorimotor, visual, default mode, auditory, and right executive control networks were used to construct connection matrices. Topological properties of those sub-networks were investigated. Results: Compared to that in the GRE group, four edges with higher functional connectivity were noted in the non-GRE group. Moreover, 21 edges with higher functional connectivity were identified in the non-GRE group compared to the healthy group. All significant alterations in functional edges belong to the visual network. Increased global efficiency and decreased shortest path lengths were noted in the non-GRE group compared to the GRE and healthy groups. Compared with that in the healthy group, nodal efficiency of three nodes was higher in the GRE and non-GRE groups and the degree centrality of six nodes was altered in the non-GRE group. Conclusion: Temporal lobe gliomas in the left hemisphere and GRE altered visual networks in an opposing manner. These findings provide a novel insight into brain network alterations induced by GRE.
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Affiliation(s)
- Shengyu Fang
- Department of Neurosurgery, Beijing Neurosurgical Institute, Beijing, China
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Chunyao Zhou
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Xing Fan
- Department of Neurosurgery, Beijing Neurosurgical Institute, Beijing, China
| | - Tao Jiang
- Department of Neurosurgery, Beijing Neurosurgical Institute, Beijing, China
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yinyan Wang
- Department of Neurosurgery, Beijing Neurosurgical Institute, Beijing, China
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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Aydin Ü, Pellegrino G, Ali OBK, Abdallah C, Dubeau F, Lina JM, Kobayashi E, Grova C. Magnetoencephalography resting state connectivity patterns as indicatives of surgical outcome in epilepsy patients. J Neural Eng 2020; 17:035007. [PMID: 32191632 DOI: 10.1088/1741-2552/ab8113] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Focal epilepsy is a disorder affecting several brain networks; however, epilepsy surgery usually targets a restricted region, the so-called epileptic focus. There is a growing interest in embedding resting state (RS) connectivity analysis into pre-surgical workup. APPROACH In this retrospective study, we analyzed Magnetoencephalography (MEG) long-range RS functional connectivity patterns in patients with drug-resistant focal epilepsy. MEG recorded prior to surgery from seven seizure-free (Engel Ia) and five non seizure-free (Engel III or IV) patients were analyzed (minimum 2-years post-surgical follow-up). MEG segments without any detectable epileptic activity were source localized using wavelet-based Maximum Entropy on the Mean method. Amplitude envelope correlation in the theta (4-8 Hz), alpha (8-13 Hz), and beta (13-26 Hz) bands were used for assessing connectivity. MAIN RESULTS For seizure-free patients, we found an isolated epileptic network characterized by weaker connections between the brain region where interictal epileptic discharges (IED) are generated and the rest of the cortex, when compared to connectivity between the corresponding contralateral homologous region and the rest of the cortex. Contrarily, non seizure-free patients exhibited a widespread RS epileptic network characterized by stronger connectivity between the IED generator and the rest of the cortex, in comparison to the contralateral region and the cortex. Differences between the two seizure outcome groups concerned mainly distant long-range connections and were found in the alpha-band. SIGNIFICANCE Importantly, these connectivity patterns suggest specific mechanisms describing the underlying organization of the epileptic network and were detectable at the individual patient level, supporting the prospect use of MEG connectivity patterns in epilepsy to predict post-surgical seizure outcome.
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Affiliation(s)
- Ümit Aydin
- Multimodal Functional Imaging Lab, Department of Physics and PERFORM Centre, Concordia University, Montreal, Québec, Canada. Authors to whom any correspondence should be addressed
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Barot N. Networks in Frontal Lobe Epilepsy. Neurosurg Clin N Am 2020; 31:319-324. [PMID: 32475482 DOI: 10.1016/j.nec.2020.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Epilepsy affects about 1% of the general population. Frontal lobe epilepsy is the second most common focal epilepsy accounting for nearly 25% of medically refractory epilepsies. This paper reviews frontal lobe epilepsy from a perspective of a network disease that may help us to understand epilepsy from the microscale of genes, to local neuronal circuits, to the macrolevel of a whole-brain network. Surgical interventions, such as ablation and resection act by removing the active target nodes in the network, while responsive neurostimulation and vagus nerve stimulation act by modulating networks at the local neuronal circuit level and whole-brain level.
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Affiliation(s)
- Niravkumar Barot
- University of Pittsburgh, Kaufmann Medical Building, 3471 Fifth Avenues, Suite 810, Pittsburgh, PA 15213, USA.
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15
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Wu X, Liu W, Wang W, Gao H, Hao N, Yue Q, Gong Q, Zhou D. Altered intrinsic brain activity associated with outcome in frontal lobe epilepsy. Sci Rep 2019; 9:8989. [PMID: 31222073 PMCID: PMC6586796 DOI: 10.1038/s41598-019-45413-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 06/06/2019] [Indexed: 02/05/2023] Open
Abstract
Frontal lobe epilepsy (FLE) is the second most common type of the focal epilepsies. Our understanding of this disease has been revolutionized over the past decade, but variable treatment outcomes persist and the underlying functional mechanisms responsible for this have yet to be deciphered. This study was designed to determine how intrinsic brain connectivity related to treatment response in patients with FLE. 50 patients with FLE and 28 healthy controls were enrolled in this study and underwent functional MRI at baseline. At the end of 12-month follow up period, all patients with FLE were classified, based on their responses to AEDs treatment, into drug-responsive and drug-refractory groups. The amplitude of low-frequency fluctuation (ALFF) was calculated amongst the three groups in order to detect regional neural function integration. The responsive group showed decreased ALFF only in the left ventromedial prefrontal cortex (vmPFC), while the refractory group showed decreased ALFF in the left vmPFC, right superior frontal gyrus (SFG), and supramarginal gyrus (SMG) relative to healthy controls. In addition, both the responsive and refractory groups showed increased ALFF in the precuneus and postcentral gyrus when compared to the healthy controls. Furthermore, the refractory group exhibited significantly decreased ALFF in the left vmPFC, right SFG and SMG, relative to the responsive group. Focal spontaneous activity, as assessed by ALFF, was associated with response to antiepileptic treatment in patients with FLE. Patients with refractory frontal lobe epilepsy exhibited decreased intrinsic brain activity. Our findings provide novel neuroimaging evidence into the mechanisms of medically-intractable FLE at the brain level.
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Affiliation(s)
- Xintong Wu
- Departments of Neurology, Huaxi MR Research Center (HMRRC), West China Hospital, Sichuan University, No. 37 GuoXue Alley, Chengdu, 610041, China
| | - Wenyu Liu
- Departments of Neurology, Huaxi MR Research Center (HMRRC), West China Hospital, Sichuan University, No. 37 GuoXue Alley, Chengdu, 610041, China
| | - Weina Wang
- Departments of Radiology, West China Hospital, Sichuan University, No. 37 GuoXue Alley, Chengdu, 610041, China
| | - Hui Gao
- Departments of Neurology, Huaxi MR Research Center (HMRRC), West China Hospital, Sichuan University, No. 37 GuoXue Alley, Chengdu, 610041, China
| | - Nanya Hao
- Departments of Neurology, Huaxi MR Research Center (HMRRC), West China Hospital, Sichuan University, No. 37 GuoXue Alley, Chengdu, 610041, China
| | - Qiang Yue
- Departments of Radiology, West China Hospital, Sichuan University, No. 37 GuoXue Alley, Chengdu, 610041, China.
| | - Qiyong Gong
- Departments of Radiology, West China Hospital, Sichuan University, No. 37 GuoXue Alley, Chengdu, 610041, China
| | - Dong Zhou
- Departments of Neurology, Huaxi MR Research Center (HMRRC), West China Hospital, Sichuan University, No. 37 GuoXue Alley, Chengdu, 610041, China.
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16
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Tavakol S, Royer J, Lowe AJ, Bonilha L, Tracy JI, Jackson GD, Duncan JS, Bernasconi A, Bernasconi N, Bernhardt BC. Neuroimaging and connectomics of drug-resistant epilepsy at multiple scales: From focal lesions to macroscale networks. Epilepsia 2019; 60:593-604. [PMID: 30889276 PMCID: PMC6447443 DOI: 10.1111/epi.14688] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 02/13/2019] [Accepted: 02/14/2019] [Indexed: 01/03/2023]
Abstract
Epilepsy is among the most common chronic neurologic disorders, with 30%-40% of patients having seizures despite antiepileptic drug treatment. The advent of brain imaging and network analyses has greatly improved the understanding of this condition. In particular, developments in magnetic resonance imaging (MRI) have provided measures for the noninvasive characterization and detection of lesions causing epilepsy. MRI techniques can probe structural and functional connectivity, and network analyses have shaped our understanding of whole-brain anomalies associated with focal epilepsies. This review considers the progress made by neuroimaging and connectomics in the study of drug-resistant epilepsies due to focal substrates, particularly temporal lobe epilepsy related to mesiotemporal sclerosis and extratemporal lobe epilepsies associated with malformations of cortical development. In these disorders, there is evidence of widespread disturbances of structural and functional connectivity that may contribute to the clinical and cognitive prognosis of individual patients. It is hoped that studying the interplay between macroscale network anomalies and lesional profiles will improve our understanding of focal epilepsies and assist treatment choices.
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Affiliation(s)
- Shahin Tavakol
- Multimodal Imaging and Connectome Analysis Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Jessica Royer
- Multimodal Imaging and Connectome Analysis Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Alexander J Lowe
- Multimodal Imaging and Connectome Analysis Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Leonardo Bonilha
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina
| | - Joseph I Tracy
- Cognitive Neuroscience and Brain Mapping Laboratory, Thomas Jefferson University Hospitals/Sidney Kimmel Medical College, Philadelphia, Pennsylvania
| | - Graeme D Jackson
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia
| | | | - Andrea Bernasconi
- Neuroimaging of Epilepsy Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Neda Bernasconi
- Neuroimaging of Epilepsy Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Boris C Bernhardt
- Multimodal Imaging and Connectome Analysis Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
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17
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Saunders J, Carlson HL, Cortese F, Goodyear BG, Kirton A. Imaging functional motor connectivity in hemiparetic children with perinatal stroke. Hum Brain Mapp 2018; 40:1632-1642. [PMID: 30447082 DOI: 10.1002/hbm.24474] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 11/02/2018] [Accepted: 11/05/2018] [Indexed: 01/18/2023] Open
Abstract
Perinatal stroke causes lifelong disability, particularly hemiparetic cerebral palsy. Arterial ischemic strokes (AIS) are large, cortical, and subcortical injuries acquired near birth due to acute occlusion of the middle cerebral artery. Periventricular venous infarctions (PVI) are smaller, subcortical strokes acquired prior to 34 weeks gestation involving injury to the periventricular white matter. Both stroke types can damage motor pathways, thus, we investigated resulting alterations in functional motor networks and probed function. We measured blood oxygen level dependent (BOLD) fluctuations at rest in 38 participants [10 arterial patients (age = 14.7 ± 4.1 years), 10 venous patients (age = 13.5 ± 3.7 years), and 18 typically developing controls (TDCs) (age = 15.3 ± 5.1 years)] and explored strength and laterality of functional connectivity in the motor network. Inclusion criteria included MRI-confirmed, unilateral perinatal stroke, symptomatic hemiparetic cerebral palsy, and 6-19 years old at time of imaging. Seed-based functional connectivity analyses measured temporal correlations in BOLD response over the whole brain using primary motor cortices as seeds. Laterality indices based on mean z-scores in lesioned and nonlesioned hemispheres explored laterality. In AIS patients, significant differences in both strength and laterality of motor network connections were observed compared with TDCs. In PVI patients, motor networks largely resembled those of healthy controls, albeit slightly weaker and asymmetric, despite subcortical damage and hemiparesis. Functional connectivity strengths were not related to motor outcome scores for either stroke group. This study serves as a foundation to better understand how resting-state fMRI can assess motor functional connectivity and potentially be applied to explore mechanisms of interventional therapies after perinatal stroke.
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Affiliation(s)
- Jennifer Saunders
- Neuroscience Graduate Program, University of Calgary, Calgary, Alberta, Canada.,Calgary Pediatric Stroke Program, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Helen L Carlson
- Calgary Pediatric Stroke Program, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Filomeno Cortese
- Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Bradley G Goodyear
- Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Departments of Radiology and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Adam Kirton
- Calgary Pediatric Stroke Program, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Departments of Pediatrics and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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18
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Brain network alteration in patients with temporal lobe epilepsy with cognitive impairment. Epilepsy Behav 2018; 81:41-48. [PMID: 29475172 DOI: 10.1016/j.yebeh.2018.01.024] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 01/15/2018] [Accepted: 01/18/2018] [Indexed: 02/02/2023]
Abstract
The aims of this study were to investigate the brain network alternation in patients with temporal lobe epilepsy (TLE) with and without cognitive impairment (CI) using functional magnetic resonance imaging (fMRI) and to further explore the potential mechanisms of epilepsy-induced CI. Forty patients with TLE and nineteen healthy controls (HCs) were recruited for this study. All participants received the Montreal Cognitive Assessment (MoCA) test, and the patients were divided into CI (n=21) and cognitive nonimpairment (CNI) groups (n=19) according to MoCA performance. Functional connectivity (FC) differences of resting state networks (RSNs) were compared among the CI, CNI, and HC groups. Correlation between FC and MoCA scores was also observed. When compared with the HC group, significantly decreased FC between medial visual network (mVN) and left frontoparietal network (lFPN) as well as between visuospatial network (VSN) and the anterior default mode network (aDMN) were revealed in both CI and CNI groups. In addition, significantly decreased FC between lFPN and executive control network (ECN) and increased FC between ECN and sensorimotor-related network (SMN) were found in CNI and CI groups, respectively. When compared with the CNI group, the CI group exhibited significant increased FC between ECN and lFPN as well as between ECN and SMN. Moreover, in the CI group, FC between ECN and lFPN showed negative correlation with attention scores. Our findings suggested that cognitive networks are different from epileptic networks, and the increased FC between RSNs closely related to cognitive function changes may help us to further understand the mechanism of CI in TLE.
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Xiao F, An D, Zhou D. Functional MRI-based connectivity analysis: A promising tool for the investigation of the pathophysiology and comorbidity of epilepsy. Seizure 2017; 44:37-41. [DOI: 10.1016/j.seizure.2016.10.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 09/14/2016] [Accepted: 10/03/2016] [Indexed: 12/25/2022] Open
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20
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Dong L, Li H, He Z, Jiang S, Klugah-Brown B, Chen L, Wang P, Tan S, Luo C, Yao D. Altered local spontaneous activity in frontal lobe epilepsy: a resting-state functional magnetic resonance imaging study. Brain Behav 2016; 6:e00555. [PMID: 27843705 PMCID: PMC5102650 DOI: 10.1002/brb3.555] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/11/2016] [Accepted: 08/01/2016] [Indexed: 11/09/2022] Open
Abstract
PURPOSE The purpose of this study was to investigate the local spatiotemporal consistency of spontaneous brain activity in patients with frontal lobe epilepsy (FLE). METHOD Eyes closed resting-state functional magnetic resonance imaging (fMRI) data were collected from 19 FLE patients and 19 age- and gender-matched healthy controls. A novel measure, named FOur-dimensional (spatiotemporal) Consistency of local neural Activities (FOCA) was used to assess the spatiotemporal consistency of local spontaneous activity (emphasizing both local temporal homogeneity and regional stability of brain activity states). Then, two-sample t test was performed to detect the FOCA differences between two groups. Partial correlations between the FOCA values and durations of epilepsy were further analyzed. KEY FINDINGS Compared with controls, FLE patients demonstrated increased FOCA in distant brain regions including the frontal and parietal cortices, as well as the basal ganglia. The decreased FOCA was located in the temporal cortex, posterior default model regions, and cerebellum. In addition, the FOCA measure was linked to the duration of epilepsy in basal ganglia. SIGNIFICANCE Our study suggested that alterations of local spontaneous activity in frontoparietal cortex and basal ganglia was associated with the pathophysiology of FLE; and the abnormality in frontal and default model regions might account for the potential cognitive impairment in FLE. We also presumed that the FOCA measure had potential to provide important insights into understanding epilepsy such as FLE.
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Affiliation(s)
- Li Dong
- Key Laboratory for NeuroInformation of Ministry of Education Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province School of Life Science and Technology University of Electronic Science and Technology of China Chengdu China
| | - Hechun Li
- Key Laboratory for NeuroInformation of Ministry of Education Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province School of Life Science and Technology University of Electronic Science and Technology of China Chengdu China
| | - Zhongqiong He
- Key Laboratory for NeuroInformation of Ministry of Education Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province School of Life Science and Technology University of Electronic Science and Technology of China Chengdu China
| | - Sisi Jiang
- Key Laboratory for NeuroInformation of Ministry of Education Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province School of Life Science and Technology University of Electronic Science and Technology of China Chengdu China
| | - Benjamin Klugah-Brown
- Key Laboratory for NeuroInformation of Ministry of Education Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province School of Life Science and Technology University of Electronic Science and Technology of China Chengdu China
| | - Lin Chen
- Key Laboratory for NeuroInformation of Ministry of Education Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province School of Life Science and Technology University of Electronic Science and Technology of China Chengdu China
| | - Pu Wang
- Key Laboratory for NeuroInformation of Ministry of Education Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province School of Life Science and Technology University of Electronic Science and Technology of China Chengdu China
| | - Song Tan
- Key Laboratory for NeuroInformation of Ministry of Education Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province School of Life Science and Technology University of Electronic Science and Technology of China Chengdu China
| | - Cheng Luo
- Key Laboratory for NeuroInformation of Ministry of Education Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province School of Life Science and Technology University of Electronic Science and Technology of China Chengdu China
| | - Dezhong Yao
- Key Laboratory for NeuroInformation of Ministry of Education Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province School of Life Science and Technology University of Electronic Science and Technology of China Chengdu China
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Dong L, Wang P, Peng R, Jiang S, Klugah-Brown B, Luo C, Yao D. Altered basal ganglia-cortical functional connections in frontal lobe epilepsy: A resting-state fMRI study. Epilepsy Res 2016; 128:12-20. [PMID: 27792884 DOI: 10.1016/j.eplepsyres.2016.10.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 10/05/2016] [Accepted: 10/24/2016] [Indexed: 10/20/2022]
Abstract
OBJECTIVES The purpose of this study was to investigate alterations of basal ganglia-cortical functional connections in patients with frontal lobe epilepsy (FLE). METHOD Resting-state functional magnetic resonance imaging (fMRI) data were gathered from 19 FLE patients and 19 age- and gender-matched healthy controls. Functional connectivity (FC) analysis was used to assess the functional connections between basal ganglia and cerebral cortex. Regions of interest, including the left/right caudate, putamen, pallidum and thalamus, were selected as the seeds. Two sample t-test was used to determine the difference between patients and controls, while controlling the age, gender and head motions. RESULTS Compared with controls, FLE patients demonstrated increased FCs between basal ganglia and regions including the right fusiform gyrus, the bilateral cingulate gyrus, the precuneus and anterior cingulate gyrus. Reduced FCs were mainly located in a range of brain regions including the bilateral middle occipital gyrus, the ventral frontal lobe, the right putamen, the left fusiform gyrus and right rolandic operculum. In addition, the relationships between basal ganglia-cingulate connections and durations of epilepsy were also found. CONCLUSION The alterations of functional integrity within the basal ganglia, as well as its connections to limbic and ventral frontal areas, indicate the important roles of the basal ganglia-cortical functional connections in FLE, and provide new insights in the pathophysiological mechanism of FLE.
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Affiliation(s)
- Li Dong
- Key Laboratory for NeuroInformation of Ministry of Education, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Pu Wang
- Key Laboratory for NeuroInformation of Ministry of Education, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Rui Peng
- Key Laboratory for NeuroInformation of Ministry of Education, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Sisi Jiang
- Key Laboratory for NeuroInformation of Ministry of Education, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Benjamin Klugah-Brown
- Key Laboratory for NeuroInformation of Ministry of Education, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Cheng Luo
- Key Laboratory for NeuroInformation of Ministry of Education, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China.
| | - Dezhong Yao
- Key Laboratory for NeuroInformation of Ministry of Education, Center for Information in Medicine, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
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Teghipco A, Hussain A, Tivarus ME. Disrupted functional connectivity affects resting state based language lateralization. NEUROIMAGE-CLINICAL 2016; 12:910-927. [PMID: 27882297 PMCID: PMC5114586 DOI: 10.1016/j.nicl.2016.10.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 09/10/2016] [Accepted: 10/20/2016] [Indexed: 12/01/2022]
Abstract
Pre-operative assessment of language localization and lateralization is critical to preserving brain function after lesion or epileptogenic tissue resection. Task fMRI (t-fMRI) has been extensively and reliably used to this end, but resting state fMRI (rs-fMRI) is emerging as an alternative pre-operative brain mapping method that is independent of a patient's ability to comply with a task. We sought to evaluate if language lateralization obtained from rs-fMRI can replace standard assessment using t-fMRI. In a group of 43 patients scheduled for pre-operative fMRI brain mapping and 17 healthy controls, we found that existing methods of determining rs-fMRI lateralization by considering interhemispheric and intrahemispheric functional connectivity are inadequate compared to t-fMRI when applied to the language network. We determined that this was attributable to widespread but nuanced disturbances in the functional connectivity of the language network in patients. We found changes in interhemispheric and intrahemispheric functional connectivity that were dependent on lesion location, and particularly impacted patients with lesions in the left temporal lobe. We then tested whether a simpler measure of functional connectivity to the language network has a better relation to t-fMRI based language lateralization. Remarkably, we found that functional connectivity between the language network and the frontal pole, and superior frontal gyrus, as well as the supramarginal gyrus, significantly correlated to task based language lateralization indices in both patients and healthy controls. These findings are consistent with prior work with epilepsy patients, and provide a framework for evaluating language lateralization at rest. Existing methods of determining rs-fMRI lateralization are inadequate for language. Functional connectivity to language network correlates with task lateralization. Lesion location affects functional connectivity. Lesions exhibit some interhemispheric hyperconnectivity within language network.
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Affiliation(s)
- Alex Teghipco
- Rochester Center for Brain Imaging, University of Rochester, USA
| | - Ali Hussain
- Department of Imaging Sciences, University of Rochester, USA
| | - Madalina E Tivarus
- Rochester Center for Brain Imaging, University of Rochester, USA; Department of Imaging Sciences, University of Rochester, USA
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23
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Cognitive deterioration in adult epilepsy: Does accelerated cognitive ageing exist? Neurosci Biobehav Rev 2016; 64:1-11. [PMID: 26900650 DOI: 10.1016/j.neubiorev.2016.02.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 01/29/2016] [Accepted: 02/01/2016] [Indexed: 11/21/2022]
Abstract
A long-standing concern has been whether epilepsy contributes to cognitive decline or so-called 'epileptic dementia'. Although global cognitive decline is generally reported in the context of chronic refractory epilepsy, it is largely unknown what percentage of patients is at risk for decline. This review is focused on the identification of risk factors and characterization of aberrant cognitive trajectories in epilepsy. Evidence is found that the cognitive trajectory of patients with epilepsy over time differs from processes of cognitive ageing in healthy people, especially in adulthood-onset epilepsy. Cognitive deterioration in these patients seems to develop in a 'second hit model' and occurs when epilepsy hits on a brain that is already vulnerable or vice versa when comorbid problems develop in a person with epilepsy. Processes of ageing may be accelerated due to loss of brain plasticity and cognitive reserve capacity for which we coin the term 'accelerated cognitive ageing'. We believe that the concept of accelerated cognitive ageing can be helpful in providing a framework understanding global cognitive deterioration in epilepsy.
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Bachtiar V, Near J, Johansen-Berg H, Stagg CJ. Modulation of GABA and resting state functional connectivity by transcranial direct current stimulation. eLife 2015; 4:e08789. [PMID: 26381352 PMCID: PMC4654253 DOI: 10.7554/elife.08789] [Citation(s) in RCA: 157] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 09/18/2015] [Indexed: 12/26/2022] Open
Abstract
We previously demonstrated that network level functional connectivity in the human brain could be related to levels of inhibition in a major network node at baseline (Stagg et al., 2014). In this study, we build upon this finding to directly investigate the effects of perturbing M1 GABA and resting state functional connectivity using transcranial direct current stimulation (tDCS), a neuromodulatory approach that has previously been demonstrated to modulate both metrics. FMRI data and GABA levels, as assessed by Magnetic Resonance Spectroscopy, were measured before and after 20 min of 1 mA anodal or sham tDCS. In line with previous studies, baseline GABA levels were negatively correlated with the strength of functional connectivity within the resting motor network. However, although we confirm the previously reported findings that anodal tDCS reduces GABA concentration and increases functional connectivity in the stimulated motor cortex; these changes are not correlated, suggesting they may be driven by distinct underlying mechanisms. DOI:http://dx.doi.org/10.7554/eLife.08789.001
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Affiliation(s)
- Velicia Bachtiar
- Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Jamie Near
- Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Canada
| | - Heidi Johansen-Berg
- Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Charlotte J Stagg
- Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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Wu Y, Ji GJ, Zang YF, Liao W, Jin Z, Liu YL, Li K, Zeng YW, Fang F. Local Activity and Causal Connectivity in Children with Benign Epilepsy with Centrotemporal Spikes. PLoS One 2015. [PMID: 26225427 PMCID: PMC4520539 DOI: 10.1371/journal.pone.0134361] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The aim of the current study was to localize the epileptic focus and characterize its causal relation with other brain regions, to understand the cognitive deficits in children with benign childhood epilepsy with centrotemporal spikes (BECTS). Resting-state functional magnetic resonance imaging (fMRI) was performed in 37 children with BECTS and 25 children matched for age, sex and educational achievement. We identified the potential epileptogenic zone (EZ) by comparing the amplitude of low frequency fluctuation (ALFF) of spontaneous blood oxygenation level dependent fMRI signals between the groups. Granger causality analysis was applied to explore the causal effect between EZ and the whole brain. Compared with controls, children with BECTS had significantly increased ALFF in the right postcentral gyrus and bilateral calcarine, and decreased ALFF in the left anterior cingulate cortex, bilateral putaman/caudate, and left cerebellum. ALFF values in the putaman/caudate were positively correlated with verbal IQ scores in patients. The ALFF values in cerebellum and performance IQ scores were negatively correlated in patients. These results suggest that ALFF disturbances in the putaman/caudate and cerebellum play an important role in BECTS cognitive dysfunction. Compared with controls, the patients showed increased driving effect from the EZ to the right medial frontal cortex and posterior cingulate cortex and decreased causal effects from the EZ to left inferior frontal gyrus. The causal effect of the left inferior frontal gyrus negatively correlated with disease duration, which suggests a relation between the epileptiform activity and language impairment. All together, these findings provide additional insight into the neurophysiological mechanisms of epilepitogenisis and cognitive dysfunction associated with BECTS.
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Affiliation(s)
- Yun Wu
- Department of Neurology, Beijing Children’s Hospital Affiliated to Capital Medical University, Beijing, China
- * E-mail: (YW); (FF)
| | - Gong-Jun Ji
- Laboratory of Cognitive Neuropsychology, Department of Medical Psychology, Anhui Medical University, Hefei, China
- Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, China
- Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China
| | - Yu-Feng Zang
- Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, China
- Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China
| | - Wei Liao
- Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, China
- Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China
| | - Zhen Jin
- fMRI Center, The 306 Hospital of People’s Liberation Army, Beijing, China
| | - Ya-Li Liu
- fMRI Center, The 306 Hospital of People’s Liberation Army, Beijing, China
| | - Ke Li
- fMRI Center, The 306 Hospital of People’s Liberation Army, Beijing, China
| | - Ya-Wei Zeng
- fMRI Center, The 306 Hospital of People’s Liberation Army, Beijing, China
| | - Fang Fang
- Department of Neurology, Beijing Children’s Hospital Affiliated to Capital Medical University, Beijing, China
- * E-mail: (YW); (FF)
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Pijnenburg M, Brumagne S, Caeyenberghs K, Janssens L, Goossens N, Marinazzo D, Swinnen SP, Claeys K, Siugzdaite R. Resting-State Functional Connectivity of the Sensorimotor Network in Individuals with Nonspecific Low Back Pain and the Association with the Sit-to-Stand-to-Sit Task. Brain Connect 2015; 5:303-11. [PMID: 25557846 DOI: 10.1089/brain.2014.0309] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Individuals with nonspecific low back pain (NSLBP) show a decreased sit-to-stand-to-sit (STSTS) performance. This dynamic sensorimotor task requires integration of sensory and motor information in the brain. Therefore, a better understanding of the underlying central mechanisms of impaired sensorimotor performance and the presence of NSLBP is needed. The aims of this study were to characterize differences in sensorimotor functional connectivity in individuals with NSLBP and to investigate whether the patterns of sensorimotor functional connectivity underlie the impaired STSTS performance. Seventeen individuals with NSLBP and 17 healthy controls were instructed to perform five consecutive STSTS movements as fast as possible. Based on the center of pressure displacement, the total duration of the STSTS task was determined. In addition, resting-state functional connectivity images were acquired and analyzed on a multivariate level using both functional connectivity density mapping and independent component analysis. Individuals with NSLBP needed significantly more time to perform the STSTS task compared to healthy controls. In addition, decreased resting-state functional connectivity of brain areas related to the integration of sensory and/or motor information was shown in the individuals with NSLBP. Moreover, the decreased functional connectivity at rest of the left precentral gyrus and lobule IV and V of the left cerebellum was associated with a longer duration of the STSTS task in both individuals with NSLBP and healthy controls. In summary, individuals with NSLBP showed a reorganization of the sensorimotor network at rest, and the functional connectivity of specific sensorimotor areas was associated with the performance of a dynamic sensorimotor task.
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Affiliation(s)
- Madelon Pijnenburg
- 1 Department of Rehabilitation Sciences, KU Leuven-University of Leuven , Leuven, Belgium
| | - Simon Brumagne
- 1 Department of Rehabilitation Sciences, KU Leuven-University of Leuven , Leuven, Belgium
| | - Karen Caeyenberghs
- 2 Department of Physical Therapy and Motor Rehabilitation, University of Ghent , Ghent, Belgium .,3 Department of Movement and Sports Sciences, University of Ghent , Ghent, Belgium
| | - Lotte Janssens
- 1 Department of Rehabilitation Sciences, KU Leuven-University of Leuven , Leuven, Belgium
| | - Nina Goossens
- 1 Department of Rehabilitation Sciences, KU Leuven-University of Leuven , Leuven, Belgium
| | | | - Stephan P Swinnen
- 5 Department of Kinesiology, KU Leuven-University of Leuven , Leuven, Belgium
| | - Kurt Claeys
- 6 Department of Rehabilitation Sciences, KU Leuven-University of Leuven , Leuven, Belgium
| | - Roma Siugzdaite
- 4 Department of Data Analysis, University of Ghent , Ghent, Belgium
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27
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Altered intrinsic connectivity networks in frontal lobe epilepsy: a resting-state fMRI study. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2014; 2014:864979. [PMID: 25525456 PMCID: PMC4261631 DOI: 10.1155/2014/864979] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 10/12/2014] [Accepted: 11/02/2014] [Indexed: 11/18/2022]
Abstract
Examining the resting-state networks (RSNs) may help us to understand the neural mechanism of the frontal lobe epilepsy (FLE). Resting-state functional MRI (fMRI) data were acquired from 46 patients with FLE (study group) and 46 age- and gender-matched healthy subjects (control group). The independent component analysis (ICA) method was used to identify RSNs from each group. Compared with the healthy subjects, decreased functional connectivity was observed in all the networks; however, in some areas of RSNs, functional connectivity was increased in patients with FLE. The duration of epilepsy and the seizure frequency were used to analyze correlation with the regions of interest (ROIs) in the nine RSNs to determine their influence on FLE. The functional network connectivity (FNC) was used to study the impact on the disturbance and reorganization of FLE. The results of this study may offer new insight into the neuropathophysiological mechanisms of FLE.
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28
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Recent seizure activity alters motor organization in frontal lobe epilepsy as revealed by task-based fMRI. Epilepsy Res 2014; 108:1286-98. [PMID: 25052708 DOI: 10.1016/j.eplepsyres.2014.06.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 05/26/2014] [Accepted: 06/13/2014] [Indexed: 11/20/2022]
Abstract
PURPOSE Patients with frontal lobe epilepsy (FLE) commonly demonstrate motor impairments, suggesting that frontal lobe seizures affect motor function. However, the underlying mechanisms of these deficits are not known, nor has any study systematically examined motor organization in these patients. We therefore examined cortical motor organization in a group of adult patients with FLE, using task-based fMRI. METHODS Eleven right FLE patients, six left FLE patients, and ten control subjects underwent task-based fMRI. Two tasks were performed using the right and left hands separately, and both hands together. The first task was a finger-tapping task and the second task was a more complex coordination task. Functional MR data were compared between patient groups and controls. A laterality index of brain activation was also calculated between the epileptic and healthy hemisphere to determine hemispheric dominance during task performance to explore its relationship with a variety of patient-specific epilepsy factors. RESULTS Overall, right FLE patients demonstrated decreased BOLD activity in the epileptic hemisphere and increased BOLD activity in the healthy hemisphere compared to controls (p<0.05). The comparison of left FLE patients to controls provided less conclusive differences, possibly due to the low number of left FLE patients studied. Laterality indices of the coordination task were positively correlated to the number of months since the last seizure in both patient groups (right FLE: rs=0.779, left FLE: rs=0.943). Patients that had experienced a recent seizure relied more on the sensorimotor cortex of the healthy hemisphere during task performance, compared to those that were relatively seizure free (p<0.05). SIGNIFICANCE Patients with FLE exhibited changes in motor BOLD activity that was dependent on the duration of seizure freedom. These results demonstrate the presence of seizure-related alteration of cortical motor organization in FLE, which may underlie the motor deficits seen in these patients.
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29
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Lasarge CL, Danzer SC. Mechanisms regulating neuronal excitability and seizure development following mTOR pathway hyperactivation. Front Mol Neurosci 2014; 7:18. [PMID: 24672426 PMCID: PMC3953715 DOI: 10.3389/fnmol.2014.00018] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 02/27/2014] [Indexed: 01/19/2023] Open
Abstract
The phosphatidylinositol-3-kinase/phosphatase and tensin homolog (PTEN)-mammalian target of rapamycin (mTOR) pathway regulates a variety of neuronal functions, including cell proliferation, survival, growth, and plasticity. Dysregulation of the pathway is implicated in the development of both genetic and acquired epilepsies. Indeed, several causal mutations have been identified in patients with epilepsy, the most prominent of these being mutations in PTEN and tuberous sclerosis complexes 1 and 2 (TSC1, TSC2). These genes act as negative regulators of mTOR signaling, and mutations lead to hyperactivation of the pathway. Animal models deleting PTEN, TSC1, and TSC2 consistently produce epilepsy phenotypes, demonstrating that increased mTOR signaling can provoke neuronal hyperexcitability. Given the broad range of changes induced by altered mTOR signaling, however, the mechanisms underlying seizure development in these animals remain uncertain. In transgenic mice, cell populations with hyperactive mTOR have many structural abnormalities that support recurrent circuit formation, including somatic and dendritic hypertrophy, aberrant basal dendrites, and enlargement of axon tracts. At the functional level, mTOR hyperactivation is commonly, but not always, associated with enhanced synaptic transmission and plasticity. Moreover, these populations of abnormal neurons can affect the larger network, inducing secondary changes that may explain paradoxical findings reported between cell and network functioning in different models or at different developmental time points. Here, we review the animal literature examining the link between mTOR hyperactivation and epileptogenesis, emphasizing the impact of enhanced mTOR signaling on neuronal form and function.
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Affiliation(s)
- Candi L Lasarge
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center Cincinnati, OH, USA
| | - Steve C Danzer
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center Cincinnati, OH, USA ; Department of Anesthesia, University of Cincinnati Cincinnati, OH, USA ; Department of Pediatrics, University of Cincinnati Cincinnati, OH, USA
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Abstract
Recent resting-state functional MRI (rs-fMRI) studies have demonstrated that the human brain is composed of several essential large-scale functional brain networks, including the "default-mode network". We analyzed electrocorticogram data from four patients with intractable focal epilepsy and compared the extent of these large-scale functional brain networks with propagation pathways of ictal discharge. We found that large-scale functional brain networks had markedly similar spatial patterns compared with multisite ictal fast activity, suggesting that some epileptic activity propagates along large-scale functional brain networks. Given that decreased functional connectivity in large-scale functional brain networks has been reported in patients with focal epilepsy, ictal propagation may lead to chronic alteration of normal functional networks in the brain.
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Affiliation(s)
- Taira Uehara
- Department of Neurology, Neurological Institute Graduate School of Medical Sciences, Kyushu University
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